Method of introducing additional agents into matallurgical baths



June 8 1926. 587,600

0. NIELSEN METHOD OF INTRODUCING ADDITIONAL AGENTS INTO METALLURGICALBATHS Filed Dec. 4, 1924 Jmverzfor n L P '5 3 oaired dune i3,

My inventionreiates to new method introducing additional agents intogical baths, and more especially to method of addin chemical substancesto inert metallurgical baths, for instance in tionwith the refiningprocess for copper, and the chief object my invention is to obviate thedisadvantages of the so-cailed poling recess, that is the process ofrefinin w ich essentially consists in adding o les of green wood to themetallurgical ath, in order to bring about the refining. According to myinvention the process of refinin is carried out in two successive steps,viz in first introducing into the molten mass of the bath an agent ingaseous form or a stream of oxidizing gas, and thereupon introducing areducing agent, which may be gaseous, liquid or also solid, in thelatter case in round or crushed condition.

In or er to explain my invention more fully, I'may refer, for example tothe refining process for copper by treating the same in raw condition ina reverberatory furnace. This process, as known, is carried out byblowin compressed air through a tube mto the ath of molten copper. Inmodern practice the tube serving for the introduction of the compressedair terminates below the surface of the bath, in order to have theoxidation proceed most eifectively. The entire copper bath will thus bemechanically a itated, as if being in a state of boiling, by the actionof the gas rising from the end of the tube; the motion of the baththereby will greatly assist the gas introduced thereinto in beindistributed all over the mass contained in t e bath. If thus theimpurities contained in the latter have been removed, the copper willtake up ox gen as if in solution, and it will at this time ein anintermediate condition, in which it is only partly or imperfectlyrefined. In this case the percentage of oxygen contained in the copperwill amount to about 0.6 percent. In or or to complete the process ofrefining, this amount of oxygen must also be removed from the bath andthis had heretofore been effected by the above-mentioned process ofpoling, that is by introducing poles of green .wood into the bath. Thesteam and hydrocarbons thus introduced will act on the bath in such away, that the steam will cause the bath to be greatly agitated and thehydrocarbons wil take up the oxygen contained in the bath, thus'exertinga reducing eflect bath is very crude volition is provide a efiicient ofrefining. I am aware of as a substitute for the poiing process there hadbeen proposed to empoy tar-oil or petroleum, that is liquid fuels. Thisprom ess, however, has been utterly unsuccessful for two reasons.Firstly, to introduce a substance of the kind mentioned into the bath isconnected with danger, and secondly, the liquid fuel thus introducedinto the bath will only to a small extent be utilized for the pur ose ofreduction, so that the efiiciency of t is process will necessarily bevery poor. By t e refining method according to my invention, theintroduction of the liquid fuel as a reducing and refining agent may becarried out absolutely without danger and a complete reduction of thebath will be at- 39 tained with a very small quantity of oil or otherreducing agents. The process accordmg to my invention, as may bementioned by the way, has been employed in actual practics and has metwith a complete success. Inorder to properly meet the conditions existmgin the bath, when the refining is intended, the fact must be taken intoconsideration, that the temperature of the fur-- nace amounts to from1200 to 1300 degreesoo centlgrade. By introducing the oil or'other:reduclng agent into the bath through the tube, even if terminating abovethe level of the bath, there will be heavy puflin not to say anexplosion, and the oil will be burnt up-by the oxygen of the air andthus be utilized only to a very small extent for the i desired purposeof bringin about a reduction of the co per. In ad ition to this, if theorifice of t e tube terminates below the level of the bath, the tubewould either melt away or become clogged u so that it will be unable toperform the esired functions.

My invention will be more fully understood by reference to theaccompanyin 106 drawing, which represents diagrammat1cal ly an exam 1eof an arrangement. and combination' 0 parts, by which my invention maybe carried out in practice.

In the drawing D designates the furnace 110 containing the metallurgicalbath, for instance molten copper containing oxygen.

The coritainer A is filled with a suitable reducing a out, which in thepresent case may be an oi, or also a reducm substance in round orcrushed solid con ition, such as or instance calcium carbide charcoal,or the like. The steel-bottle l3 contains a comfpressed gas of suitablecharacter, such as or instance carbonic acid, nitro en, or the like, oralso steam which may e substituted for these gases. The bottle B isprovided with a valve e, which is connected with the container A by thetube f. The container A'is rovided with a safet valve 9 at its top andwith an outlet pipe at its bottom, the outlet pipe h being provided witha cook or valve 77., by means of which it may be connected with the pipeThe latter is connected to the pipe f at t e point f indicated in thedrawin The junction f, of the pipe I and the pipe f, as well as thejunction 7, of the outlet ipe h of the container with the horizontaipart of the pipe f, serves for the successive introduction of the tworeducing agents into the bath according to my invention, said agentsbeing contained in the bottle B and the cor. tainer A respectively. Afurther valve or cock 2' is provided in the pipe f between the junctionsf and i The device described will operate as follows. Supposing thecopper-bath be in proper condition in the furnace D for commencing withthe process of refining, the device may be put in operation by openingthe valve 6, the valves 2 and it, being closed at this time; the gascontained in the bottle B will now be able to pass into the container A.in order to facilitate the passage of gas from the bottle B into thecontainer A, the safety valve 9 rovided on the latter may be lifted fora s ort time. The end of the pipe 0, which joins the outlet pipe it andthe pipe f, at the point of junction f is introduced at its orifice intothe bath contained in the furnace D, as shown in the drawing and thereuon the valve 2' is opened for some time. A'ter a certain time the valve6 is again closed, thus preventing an immediate supply of gas from thecontainer 13 to the bath of the furnace D, and the valve h, is nowopened. By this a part of the liquid agent contained in the container Awill be forced through the outlet pipe it into the pipe C and throughthe orifice of the same into the bath of the furnace D.

The inert gas for instance carbonic acid;

diately.above.the level of the bath. Carbonic acid will thus enter thebath and move therein in upward direction. By reason of the fact, thatthe gas dischargin from the orifice of the ipe G is in cold condition,the orifice of t e pipe, 0 will not be damaged by the temperature of thebath, and no 0 oggingaip of the orifice ormelting of the same can thustake lace. inthis manner carbonic acid is supp ied to the'hath' only forsuch a time as will be HGCGSSEL? to carry on this phase of the processaccord ing to my invention; At the proper time, therefore, the valve ais closed and the valve h, o ened, so that now a part oi the agent in te container A will be forced into the bath. The carbonic acid duringthis phase ofthe process merely serves for the purpose of pressingliquid from the container A into the pipe C and therewith into ti obath. By pro erly adjusting the valve c at the top of t ebottle B itwill of course be possible to regalate the amount of gas passing frombottle '3 to the conta n-er A during his of the process.

E wish it to be understood, that in tead oi the liquid agent in thecontainer A there may also be employed an agent in gaseous form or inground or crushed solid condition as above mentioned. Also the containerA should in such case he properl constructed in order to serve for thereception of an agent gaseous or solid condition.

The process according to in may also be employed with a montage inconnection with other metalurgical processes, whereby easily oxidizablesubstances are introduced into the bath.

My present process may furthermore be advantageously employs with theprocess of remelting copper in crucibles, such as is ordinarily done infoundries. In this case the process of pol'ing could only be applied, ifcertain substances, such as phosphorous, are added to the copper, whichas a rule is not practicable in foundry work.

I claim:

The method of introducing a refining agent into a metallurgical bath,which consists in first introducing -ani inert gas into the bath, forthe purpose of removing the air contained in the conduits to the bathand invention in connection ing the refining agents to said hath,

" thereupon introducing into said hath the reducing agents in liquid,gaseous or solid condition, substantially as described and for thepurpose set forth.

in testimony whereof I hereunto aiiix signature.

OTTO NIELSEN.

